In a medium bowl, whisk together lime juice, olive oil, chopped cilantro, minced garlic, cumin, chili powder, salt, and black pepper.

Place flank steak in a resealable bag or shallow dish. Pour marinade over the steak and coat well. Seal or cover and refrigerate for at least 30 minutes or up to 4 hours for maximum flavor.

Cook rice according to package directions if not already prepared.

Warm black beans in a small saucepan over medium heat for about 5 minutes. Add a pinch of salt or cumin for extra flavor if desired.

If using fresh corn, boil briefly or saute in olive oil until tender. For frozen corn, microwave or heat on stovetop.

Preheat grill or grill pan over medium-high heat. Oil it to prevent sticking.

Remove steak from marinade, letting excess drip off. Discard the marinade. Grill steak for 4 to 5 minutes per side for medium-rare or until internal temperature reaches 130°F. Adjust time for preferred doneness.

Let steak rest 5 to 10 minutes after cooking. Slice thinly against the grain for maximum tenderness.

Spoon rice into bowls. Top with black beans, corn, and cherry tomatoes. Lay strips of sliced steak on top. Add avocado slices, red onion, feta cheese if using, and extra cilantro. Finish with lime wedges for squeezing over the bowl.